Hydrogenation of toluene on Ni-Co-Mo supported zeolite catalysts

Mixed oxides of Ni, Co and Mo supported on five zeolites -ZSM-5-a, ZSM-5-b, HY-a, HY-b and Mordenite were prepared and characterized using many techniques for use as hydrotreating catalysts. In a preliminary investigation, toluene was employed as model compound to test the catalysts in hydrogenation, as a major upgrading reaction. TGA/DSC analysis showed that the impregnation of the metals slightly affected the thermal stability of the zeolites with all catalytic samples displaying good stability up to 730oC.The XRD patterns for all the catalytic samples showed that the framework of the zeolites were retained after impregnation. XRD and TPR results confirmed the presence of molybdenum trioxide on the zeolites with NiCoMo/HY-b displaying high metal-support interaction due to low reduction temperatures. The activity results showed that toluene conversion of almost 100% and selectivity to mainly methyl-cyclohexane was achieved. The catalysts activity test showed that the zeolite support textural properties particularly surface area, pore volume and pore diameter affect the performance of the catalysts. NiCoMo/HY-b displayed the best performance after the few minutes of the reaction due to its high surface area, pore volume and average pore diameter.Keywords: Hydro treating catalysts; Hydrogenation; Toluene conversion; Surface area; Pore diamete

Mechanochemical synthesis, characterization and antimicrobial screening of Metal (II) complexes derived from amoxicillin

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Comparative evaluation of the effects of organic and inorganic fertilizers on the vegetative growth of spleen amaranth (Amaranthus dubius L)

The application of organic and inorganic fertilizers to the soil is considered as good agricultural practice because they improve the fertility of the soil and plant quality. The overall objective of the study is to compare the effects of organic fertilizers (cow dung and chicken droppings) with inorganic fertilizer (urea) on the vegetativegrowth of Amaranthus dubius. The data obtained showed that, levels of all parameters measured for both the organic and inorganic fertilizers ranges; Stem length (7.5- 64.2) cm, Stem width (2.4- 8.1) cm, Leaf length (8.0- 19.3) cm, Leaf width (3.3- 14.2) cm and Number of leaves per plant (09- 34). The mean values for the stem length, stem width, leaf length, leaf width and number of leaves per plant were evaluated and found to be higher in plants grown with urea treatment compared to values obtained from the treatments with organic manures. Data were analyzed using One-way Analysis of Variance (ANOVA) and the results were expressed as percentage difference, the differences between the mean values were determined at 95% confidence. Inorganic fertilizer resulted in significant effects at (p<0.05) compared to values obtained from the organic manures.Keywords: Amaranthus dubius, Chicken droppings, Cow dung, Ure

Selection of optimum chromium oxide-based catalysts for propane oxidehydrogenation

Propane oxidative dehydrogenation has been studied at 350-500°C, 1.0 bar and feed flow rate of 75 cm3/min over several supported chromium oxide-based catalysts. Effects of various chromium loadings, different supports, catalyst precursors and reaction conditions were investigated in an attempt to select an optimum catalyst for the reaction. Chromium oxides of different loadings ranging from 0.1 to 20 wt.% on γ-Al2O3 were tested. At 450°C, 10 wt.% loading exhibited propane conversion of 19%. γ-Al2O3 gave the best performance when MgO, TiO2, SiO2 and γ-Al2O3 were tested as supports. As a precursor, Cr(NO3)3•9H2O exhibited the best results compared with K2Cr2O7, CaCr2O7, Na2Cr2O7, Cr2SO4•12H2O and CrO3. Effects of reaction temperatures and feed compositions were also evaluated on a 10 wt.% Cr-Al-O catalyst. The maximum selectivity to propene obtained was 61% while the yield was 18%. The 10 wt.% Cr-Al-O catalyst was characterized by X-ray diffraction patterns (XRD), temperature-programmed reduction (TPR) and X-ray photoelectron spectroscopy (XPS) which confirmed the presence of both Cr3+ and Cr6+ in the calcined catalyst and, also, the predominance of Cr3+ in the spent catalyst..

Oxidehydrogenation of propane over Mn-P-O catalyst: Effects of oxygen partial pressure

Manganese phosphate catalyst was prepared and tested for the catalytic oxidative dehydrogenation of natural gas components such as propane to propylene at 1 atm and 450°-550°C. In the temperature range, the propane conversion changed from 4.1 to 40.7%, the selectivity to propylene showed insignificant change at 41%. The products obtained were propylene, ethylene, methane, CO2, and CO. Selectivity to propylene could be improved by employing low or moderate oxygen partial pressure. .King Fahd University of Petroleum and Minerals, KFUPM, Japan Petroleum Industry, JP

Oxidative dehydrogenation of propane over supported chromium-molybdenum oxides catalysts

Catalytic oxidative dehydrogenation of propane to propylene was studied on alumina-supported chromium-molybdenum oxides catalysts - 10 wt% Cr xMo(1-x)/γ-Al2O3 (where x=0-1). The catalysts are active for the reaction. Increase in the amount of molybdenum in the catalysts decreases the reducibility and changes the nature of the lattice oxygen in the catalyst as indicated by TPR and XPS data. The catalysts with lower reducibilities exhibits corresponding increase in the propylene selectivities. Alkali metals (Li, K, Cs)-doped 10 wt% Cr 0.8Mo0.2 (alkali/CrMo weight ratio of 0-0.175), shows maxima in both propane degrees of conversion and propylene yields in the ratio ranges explored. One of the catalysts (Cs/CrMo=0.125) exhibits propane conversion of 15.1% and selectivity to propylene of 64.5% at 420 °C. This is among the most promising catalysts reported for oxidative dehydrogenation of propane.

Oxidative dehydrogenation of propane over supported chromium-molybdenum oxides catalysts

Catalytic oxidative dehydrogenation of propane to propylene was studied on alumina-supported chromium-molybdenum oxides catalysts - 10 wt% Cr xMo(1-x)/γ-Al2O3 (where x=0-1). The catalysts are active for the reaction. Increase in the amount of molybdenum in the catalysts decreases the reducibility and changes the nature of the lattice oxygen in the catalyst as indicated by TPR and XPS data. The catalysts with lower reducibilities exhibits corresponding increase in the propylene selectivities. Alkali metals (Li, K, Cs)-doped 10 wt% Cr 0.8Mo0.2 (alkali/CrMo weight ratio of 0-0.175), shows maxima in both propane degrees of conversion and propylene yields in the ratio ranges explored. One of the catalysts (Cs/CrMo=0.125) exhibits propane conversion of 15.1% and selectivity to propylene of 64.5% at 420 °C. This is among the most promising catalysts reported for oxidative dehydrogenation of propane.